The present and projected investigations in this project provide a clinical model of aldose reductase delivery and a quantitative ultrastructural and biochemical methodology which permits detailed analysis of regions within each treated lens. These studies will provide a comprehensive index of lens integrity upon which to base the therapeutic effectiveness of each aldose reductase inhibitor. In addition, this work tests the hypothesis of lenticular aldose reductase in vivo and provides a model for future investigation of lens therapy.